Fighting the Arishok as a DW rogue

Always play as assassin/duelist. Hate stealth (like it only in DAO). Like this build: more dex, less cun = lower crits but enemies die from auto-attack (tried different builds in 50-60 PTs but this one like the most). With the Arishok "running" is always there, if scripted he will spike you anyway or will hit you with melee attack while you are1 metre away from him, just like 2h warrior Hawke (if I am lucky I can heal or run away from him after that). But what I do with powers: "Vendetta" to get close and then if able (I watch what the Arishok is doing) use assassination+ twin fangs. Backstab is used to get away from him usually. Sometimes have to get close to hit him to restore sta if don't have bottles of that. So in general I just repeat this combination usually 4 times (with riunning inbetween). And everything works just fine (with no DLC items; during my last PT I had a goal - used only chest armor that looks the same as the starting armor which I like very much, even if there are - and there were - better armor).